Composition for impregnating wood



Patented Dec. 27, 1927.

UNITED STATES PATENT orrlcs.

BIRNEARD WURZSCHMITT, OF UERDINGEN-NIEDERRHEIN, GERIANY, ASBIGNOR TO I. G. FARBENIN'DUSTRIE AKTIENG ESELLSCHAI'T, OF UERDINGEN-NIEDEBRHEIN, GERMANY, A CORPORATION OF GERMANY.

COMPOSITION FOR IMPREGNATING WOOD.

i No Drawing. Application filed June 17, 1926, Serial No. 116,708, and in the Netherlands June 15, 1825.

This invention relates to improvements in the art of preserving wood by impregnation and more particularly to compositions for this purpose.

Mixtures of inorganic salts with organic nitro compounds, especially the aromatic hydroxy mtro compounds, such as the dimtrophenols and dinitrocresols and their salts, have been used for a long time for the preservation of wood. Such mixtures have a. very strong fungicidal action but have the disadvantage that the aqueous solutions thereof used for impregnating corrode the iron parts of the apparatus employed in the im regnating operation.

ccording to the present invention the detrimental action of the solutions uponiron is eliminated b providin a' small amount of formaldehy ein the so utions. The formaldehyde ma be supplied as such or in the form of ormaldehyde compounds or .com lexes, such as the combinations of formal ehyde with ammonia,. amines and amides which yield formaldeh do by spontaneous decomposition under t e conditions of use.

E ially good results are obtained when in a dition to formaldehyde, primary aromatic amines and zinc compounds are added to the solutions, i. e., by the addition of formaldehyde or a com und ielding formaldehyde such as the ormal eh de ammonia or formaldehyde amine or amide combinationsr'eferred to in the im- 3 pregnating compositions described in United t ates Patent No. 1,509,066, together with the water insoluble basis zinc compounds, such as zinc oxide, referred to the same patent.

E'mmtpk-NVotbd is impregnated in the ormaldehyde known manner with the employment of pressure and vacuum with a solution which contains 1.5 kilograms of dinitrophenol, 7 .5 kilograms of sodium fluoride, 0.5 kilograms preserving agents out of the impregnated wood.

I claim:

1. A wood preserving prising an organic nitro compound and formaldehyde.

2. A wood preserving composition comprising an organic nitro com ound, a watersoluble fluoride and formal ehyde.

3. A wood preserving composition comprising an organic nitro compound, a watersoluble fluoride, a water insoluble basic zinc compound, and formaldehyde.

4. A wood preserving agent comprising an or anic nitro compound, a water-soluble fluori e, a water insoluble basic zinc compoind, an aromatic amine, and formalde- 5. In processes of impregnatlng wood with aqueous solutions containing orgamc nitro compounds in apparatus in which the solutions come in contact with iron, protecting the iron against corrosion by rovidmg a small amount of formaldehyde m-the solutions. 1

composition com- In testimony whereof, I aflix my signature.

BERNHABD 

